JP2976113B2 - Still video camera and its playback device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a still video camera and a reproducing apparatus therefor, and more particularly, to converting an analog image signal output from an image sensor into a digital image signal and recording the digital image signal in an external memory. The present invention relates to a still video camera configured and a reproducing apparatus for converting a digital image signal recorded in an external memory by the still video camera into a video signal.

<Prior Art> In recent years, instead of a conventional film camera, a still camera having a configuration in which an optical image signal from a subject is converted into an electric image signal by an image sensor and the electric image signal is stored in an external memory corresponding to a film. Video cameras are being developed,
The electric image signal stored in the external memory is reproduced and viewed on a monitor, or hard-printed by printing.

A magnetic disk is generally used as an external memory of such a still video camera, and in this case,
For example, an optical image signal obtained through an optical lens is
A photoelectric conversion is performed by an image pickup device such as D, an electric image signal obtained by the conversion is subjected to analog processing, and then electromagnetically converted using a magnetic head or the like, and magnetically recorded on a magnetic disk.

At the time of reproduction, a magnetic signal recorded on a magnetic disk is electromagnetically converted, analog processed, and displayed on a monitor.

However, in such a method of magnetic recording on a magnetic disk, both the camera and the reproducing device require a rotation drive mechanism of the magnetic disk, so that an increase in size and cost is unavoidable. Is causing delays.

In view of this point, a digital signal obtained by A / D conversion of an electric image signal obtained by an image sensor is stored in a semiconductor memory by the present applicant (Japanese Patent Laid-Open No. 59-188352). According to this, since a drive mechanism as in the case of a magnetic disk is not required, it is possible to reduce the size and weight of the camera and the reproducing apparatus and reduce the cost.

<Problems to be Solved by the Invention> By the way, in a still video camera configured to record digital image data in a semiconductor memory as described above, as shown in FIG. From the image sensor 2 on which the optical image signal is formed, converted into an electric image signal by a transfer pulse from the image sensor driving circuit 3,
After signal processing by analog processing circuit 4, A / D
The digital image signal obtained by the A / D conversion by the converter 5 is subjected to signal processing by a digital processing circuit 6 and recorded in an external memory 8 made of a semiconductor via an interface 7. These series of operations are performed at predetermined timing by the control block 9 and the clock generation circuit 10.

The reproduction of the digital image data recorded in the external memory 8 in this manner is performed by setting the external memory 8 in the reproduction apparatus as shown in FIG. After signal processing by the digital processing circuit 12, the D / A converter 1
D / A conversion is performed by 3 and signal processing is performed by the analog processing circuit 14 to be taken out as an image signal. These series of actions are
The control is performed by the control block 15 and the clock generation circuit 16 at the same drive timing as the camera side.

Here, a method of recording a digital image signal to be recorded in the external memory 8 includes the following two cases.

The first method is as shown in FIGS. 8 (A) and (B).
An analog signal corresponding to one pixel of the image sensor 2 obtained through a CDS (correlated double sampling) clamp circuit 4A and a γ correction circuit 4B is converted from analog to digital without converting the output from the image sensor 2 into a color image. In the case of recording in the memory 8, in this case, the analog signal after D / A conversion in the reproducing apparatus according to the arrangement of the color filters of the image pickup device 2 on the camera side is converted into the luminance signal Y by the color separation circuit 14A. Color difference signals RY, BY
And outputs it as a video signal by the encoder circuit 14B.

The second method is as shown in FIGS. 9 (A) and 9 (B).
After passing the output of the image sensor 2 through a CDS (correlated double sampling) clamp circuit 4A and a gamma correction circuit 4B, a colorization process, that is, a luminance signal Y and a dye signal R in a color separation circuit 4C are performed.
−Y and BY, and the A / D conversion is performed by sequentially switching each signal of the luminance signal Y and the color difference signals RY and BY by the time division circuit 4D, and is recorded in the external memory 8. In this case,
On the reproduction device side, each of the analog signals of the D / A-converted luminance signal Y and the color difference signals RY and BY is time-sequentially converted by the time-division circuit 1.
4C, is separated into a luminance signal Y and color difference signals R-Y, B-Y by a process reverse to that at the time of recording, and is output as a video signal by the encoder circuit 14B.

Then, for example, the arrangement of the color filters 2A of the image sensor 2 is
In the case of R / G / B vertical stripe as shown in Fig. 10,
The color separation circuits 14A and 4C shown in FIG. 9 and FIG. 9 have a configuration as shown in FIG.

That is, in each of the R, G, B sample and hold circuits 21, 22, and 23, each sample and hold signal (SP) generated from the control block in accordance with the output timing of each of the R, G, and B pixels.
(R, SP, G, SP, B) sample and hold the R, G, B signals, respectively, and input them to the matrix circuit 24.

 In the matrix circuit 24, Y = xR + yG + zBBR-Y, BY where x, y, and z are constants.

Is calculated and output as a video signal by the encoder circuit 14B or input to the time-division circuit 4D. In this case, unlike the first method, it is not necessary to match the frequency of the drive clock of the image sensor 2 with the frequency of the drive clock of the A / D and D / A converters 5 and 13.

In the first method, the digital image signal read from the external memory 8 may be color-separated by a digital processing circuit and then D / A converted. In the second method, the color separation and the time division processing at the time of recording are performed by A /
The digital processing may be performed by the digital processing circuit 6 after the D conversion. During reproduction, the digital processing circuit 12 separates the luminance signal Y and the chrominance signals R-Y and B-Y from each other, and performs D / A conversion on each of the signals. The signal may be input to the circuit 14B.

However, when the digital image signal is recorded in the external memory 8 by the first method, since the image output is all the luminance signal Y when the image sensor 2 of the camera is for monochrome, the color separation / Not only does it not need to perform a matrix operation, but also if a reproducing apparatus as shown in FIG. 8 is required, the video signal cannot be correctly reproduced. Accordingly, it is necessary to switch between different cameras depending on whether the camera used is monochrome or color, and whether the circuit in the playback device is a monochrome image or a color image.

When a digital image signal is recorded in the external memory 8 by the second method, when a monochrome image is recorded, only the luminance signal Y and no color difference signals RY and BY are provided.
A recording area for a luminance signal Y and color difference signals RY and BY provided for each data area A for one screen in the external memory 8 shown in FIG.
B, C, C of the recording area of all the color difference signals RY, BY in D, C,
Since 0 is written in D, the memory is wasted.

The present invention has been made in view of the above problems, and enables an image recorded in an external memory to be correctly reproduced by the same reproducing apparatus regardless of whether the image is monochrome or color.
An object of the present invention is to make it possible to effectively use the capacity of an external memory.

<Means for Solving the Problems> For this reason, the present invention converts an optical image signal of a subject obtained by an optical lens into an electric image signal by an imaging device, and sequentially converts the electric image signal into an A / D converter by an A / D converter. A still video camera configured to record a digital image signal obtained by the / D conversion into an external memory detachably connected to the camera body, wherein the digital image signal for one image of the external memory is recorded. An image color data recording means for recording data for determining whether the image is a black-and-white image or a color image is provided in the head area of the image recording area to be recorded.

A reproduction apparatus for obtaining a video signal by successively D / A converting a digital image signal input from an external memory by a D / A converter, wherein the external memory records an image with the still video camera according to claim 1. And a signal processing switching means for switching signal processing when converting an input image signal into a video signal in accordance with the image color data from.

<Operation> According to this configuration, image color data for determining whether the image is a monochrome image or a color image is recorded together with the digital image signal for each image in the head area of each image recording area of the external memory.

The playback device switches signal processing when converting an input image signal into a video signal in accordance with the image color data recorded in the external memory.

As a result, a single reproducing apparatus can correctly reproduce both a monochrome image and a color image.

Further, when recording a monochrome image with a digital image signal, it is not necessary to write 0 in the recording area of the color difference signal, and the capacity of the external memory can be saved.

<Example> Hereinafter, an example of the present invention will be described with reference to the drawings.

In FIG. 1, which shows a system configuration of a still video camera according to an embodiment in which color processing is performed on the reproduction apparatus side, the present system is controlled by a control block 31 and a clock generation circuit 32, and includes a lens, an aperture, a shutter, and the like. An optical image signal from the configured optical system 33 is converted into an analog electric image signal by an image sensor 35 such as a CCD controlled by a transfer pulse from the image sensor driver circuit 34.

The analog image signal is subjected to signal processing by the analog processing circuit 36 in the same manner as in the related art (see FIG.
The data is converted by the converter 37 into digital image data. The digital image data from the A / D converter 37 is signal-processed by a digital processing circuit 38, and then written via an interface 39 to a memory card 40 as an external memory which is detachably connected to the camera body. It is.

Here, the A / D conversion timing of the analog image signal is
Control block depending on the number of pixels of the image sensor 35 used
A reference clock signal of a frequency determined by the control block 31 and determined by the clock generation circuit 32 in accordance with a command from the control block 31 is output to the A / D converter 37, and is synchronized with the reference clock signal by one of the image sensors 35. A / D conversion is performed for each pixel.

When writing a digital image signal to the memory card 40 via the interface 39, the control block 31
From signals S ₁ of the image color data indicating black and white image or a color image is written in a memory card 40 via the interface 39 with the digital image signal to be recorded. As a result, in the memory card 40, as shown in FIG. 2, image color data, that is, data indicating a color image or data indicating a black and white image is recorded in a head area b in a recording area a for one screen. Then, data for each pixel is recorded in the subsequent area c, and image color data for black-and-white shooting or color shooting is recorded for each pixel.

As described above, the digital image is reproduced from the memory card 40 on which the digital image is recorded by using the still video camera for recording the image color data for determining whether the digital image signal is a color image or a monochrome image for each image. In this case, the reproduction is performed using the reproducing apparatus shown in FIG.

In such a playback device, when the memory card 40 is set in the playback device, the control block 41 determines whether the image is a monochrome image or a color image from data of one image to be played back via the interface 42. read image color data (shown in the drawing signal S _2).

Control block 41, each change-over switch 51 to 54 in the analog processing circuit 46 shown in FIG. 4 and outputs a signal S ₃ to the analog processing circuit 46 based on the read image color data, black and white side contact k ₁ or switching to one of the color-side contact k _2.
As a result, the data is taken in from the memory card 40 via the interface 42, and the digital processing circuit
The image signal subjected to the signal processing at 45 is subjected to D / A conversion by a D / A converter 44 according to a timing signal from a clock generation circuit 43, and then, if the image signal is obtained by monochrome processing at an analog processing circuit 46, Encoder circuit 4 directly without passing through separation circuit 46A
It is output as a video signal via 6B. Also, in the case of an image signal obtained by color photography, a color separation circuit
After being separated into a luminance signal Y and color difference signals RY and BY at 46A, they are output as video signals via an encoder circuit 46B.

In this way, an image can be correctly reproduced by the same reproducing apparatus regardless of whether the image signal is monochrome or color. This allows both black and white and color images to be stored on a single memory card 40
Can be mixed.

On the other hand, to perform color processing on the camera, the control block 31, signals S ₁ of the image color data indicating black and white image or a color image, a memory card 40 via the interface 39 with the digital image signal to be recorded Is written to. As shown in FIG. 5, the recording format of the memory card 40 in this case indicates image color data, that is, data representing a color image or a monochrome image, in a head area b in a recording area a for one screen. Data is recorded,
In the subsequent area c, only the data of the luminance signal Y for each pixel is recorded in the case of a black-and-white image, and in the case of a color image, the data of the luminance signal Y and the color difference signals RY and BY are used as in the conventional case. Is recorded. On the playback device side, the control block 41 switches the signal processing of the analog processing circuit 46 to either a monochrome image or a color image based on the read image color data.

In this case, since only the luminance signal needs to be recorded in the case of a monochrome image, the recording capacity of the memory card 40 can be saved, and the memory card 40 can be used efficiently.

<Effects of the Invention> As described above, according to the present invention, image color data for discriminating between a monochrome image and a color image is recorded together with an image signal in the head area of the image recording area of the external memory for each image. Therefore, if playback is performed using a playback device that can automatically switch between monochrome and color signal processing based on the image color data, a monochrome image and a color image can be stored in the same external memory. Even when images are mixed, one playback device can cope with the playback. Also,
In the case of a black-and-white image signal, it is not necessary to record only the luminance signal and record the color difference signal, so that the recording capacity of the external memory can be saved and the external memory can be used efficiently. Furthermore, since it is possible to read out only the image color data of the head area for a plurality of images, it is possible to know whether the image is black and white or color without having to reproduce each image one by one. It has the effect of

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a still video camera according to the present invention, FIG. 2 is a diagram showing a recording state of an external memory in the embodiment, and FIG. 3 is an embodiment of a reproducing apparatus of the present invention. FIG. 4 is a block diagram of an analog processing circuit of the reproducing apparatus, FIG. 5 is a diagram showing a recording state of an external memory in another embodiment of the present invention, and FIG. FIG. 7 is a block diagram of a conventional reproducing apparatus, and FIG. 8 is a block diagram showing a conventional example of performing colorization processing on the reproducing apparatus side.
9A is a diagram showing the camera side, FIG. 9B is a diagram showing the playback device side, and FIG. 9 is a block diagram showing a conventional example in which colorization processing is performed on the camera side, and FIG. 9A shows the camera side. Figure,
(B) is a diagram showing the reproduction device side, FIG. 10 is a diagram showing an example of a color filter of the image sensor, FIG. 11 is a configuration diagram showing a color separation circuit, and FIG. 12 performs colorization processing on the camera side. FIG. 10 is a diagram showing a conventional external memory recording state in the case. 31, 41 control block, 33 optical system, 34 image sensor drive circuit, 35 image sensor, 37 A / D converter, 40
... Memory card, 44 ... D / A converter, 46A ... Color separation circuit, 51-54 ... Switch

Continued on the front page (72) Inventor Hiroshi Ushiyama 2970 Ishikawacho, Hachioji-shi, Tokyo Konica Corporation (72) Inventor Hiroaki Arakawa 2970 Ishikawacho, Hachioji-shi, Tokyo Konica Corporation (56) References 2-107094 (JP, A) JP-A-59-171275 (JP, A) JP-A-59-188352 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) H04N 9/79 -9/898 H04N 5/91-5/956 H04N 5/907

Claims (2)

(57) [Claims] An image sensor converts an optical image signal of a subject obtained by an optical lens into an electric image signal, and a digital image signal obtained by sequentially A / D converting the electric image signal is attached to and detached from a camera body. A still video camera configured to record in an external memory that is freely connected, wherein the image is a black-and-white image or a color image in a head area of an image recording area for recording a digital image signal for one image of the external memory. A still video camera comprising image color data recording means for recording data for determining whether an image is an image. 2. A reproducing apparatus for obtaining a video signal by successively D / A converting a digital image signal inputted from an external memory by a D / A converter, wherein an image is recorded by the still video camera according to claim 1. And a signal processing means for switching a signal processing for converting an input image signal into a video signal in accordance with the image color data from the external memory.